Geometry Control for Connection Design per AISC 360-16

Connection design geometry checks such as hole size, minimum and maximum bolt spacing, bolt edge distance, and weld thickness are explained in detail under this title.

Hole Size and Applications

Maximum hole sizes of holes for bolts are given in AISC 360-16 Table J3.3.
ideCAD automatically uses these values for the design of steel connections and drawings.

TABLE J3.3M Nominal Hole Dimensions, mm
Bolt Diameter, mm	Hole Dimensions
Bolt Diameter, mm	Standard (Dia.)	Oversize (Dia.)	Short-Slot (Width x Length)	Long-Slot (Width x Length)
M16	18	20	18 x 22	18 x 40
M20	22	24	22 x 36	22 x 50
M22	24	28	24 x 30	24 x 55
M24	27	30	27 x 32	27 x 60
M27	30	35	30 x 37	30 x 67
M30	33	38	30 x 40	33 x 75
≥ M36	d+3	d+8	(d + 3) × (d + 10)	(d + 3) × 2.5d

Minimum Spacing

The distance between the centers of standard, large, and slot holes, s, is not less than 2²/3 times the nominal diameter, d, of the fastener. According to AISC 360-16, the distance between centers of standard, oversized, or slotted holes of 3D is preferred. (s ≥ 3d)
This control is done automatically and reported in bolted connections.

Minimum Edge Distance

The distance from the standard hole diameter center to the edge of the element, in any direction, cannot exceed the values given in AISC 360-16 Table J3.4.
The distance from the center of the large or slotted hole to the connected part edge cannot be less than that required for a standard hole to an edge of a connected part plus the applicable increment, C₂, from AISC 360-16 Table J3.5.
This control is done automatically and reported in bolted connections.

TABLE J3.4M Minimum Edge Distance from Center of Standard Hole to Edge of Connected Part, mm
Bolt Diameter, mm	Minimum Edge Distance
M16	22
M20	26
M22	28
M24	30
M27	34
M30	38
M36	48
≥ M36	1.25d

TABLE J3.5M Values of Edge Distance Increment C₂, mm
Nominal Diameter of Fastener	Oversized Holes	Slotted Holes
		Long Axis Perpendicular to Edge		Long Axis Parallel to Edge
		Short Slots	Long Slots	Long Axis Parallel to Edge
≤ 22	2	3	0.75d	0
24	3	3
≥ 27	3	5

Maximum Bolt Spacing and Distance to Edge

The maximum distance of the center of any bolt to the nearest edge cannot exceed 12 times the thickness of the part it connects or 150 mm.
This control is not done automatically by the ideCAD Structural. However, in the joints calculated and created by the plastic design philosophy (for example, single slip plate joints, double and single angle joints, etc.), the edge distance is 2*d, with the diameter of the bolt d, the distance between the bolts is maximum 8*d is generated.

Welding Thickness

The Effective Thickness of Partial Penetration Groove Welds

The minimum effective throat of a partial-joint-penetration groove weld cannot be less than the thickness of the weld, which will ensure the safe transfer of the calculated force and the size given in AISC 360-16 Table J2.3. Minimum weld size is determined by the thinner of the two parts joined.
This check is done automatically and reported.

Fillet Welds Effective Thickness

The minimum size of fillet welds shall be not less than the size required to transmit forces nor the size shown in AISC 360-16 Table J2.4.
This check is done automatically and reported.

Note: The points specified in AISC 360-16 J2b.2 for the maximum thickness of the filled welds are not automatically checked.

TABLE J2.3 Minimum Effective Throat of Partial-Joint-Penetration Groove Welds
Material Thickness of Thinner Part Joined, mm	Minimum Effective Throat, mm
To 6 inclusive	3
Over 6 to 13	5
Over 13 to 19	6
Over 19 to 38	8
Over 38 to 57	10
Over 57 to 150	13
Over 150	16

TABLE J2.4 Minimum Size of Fillet Welds
Material Thickness of Thinner Part Joined, mm	Minimum Effective Throat, mm
To 6 inclusive	3
Over 6 to 13	5
Over 13 to 19	6
Over 19	8

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Shear Connections per AISC 360-16

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